linux_old1/include
Andi Kleen 2c95afc1e8 perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86
The NMI watchdog uses either the fixed cycles or a generic cycles
counter. This causes a lot of conflicts with users of the PMU who want
to run a full group including the cycles fixed counter, for example
the --topdown support recently added to perf stat. The code needs to
fall back to not use groups, which can cause measurement inaccuracy
due to multiplexing errors.

This patch switches the NMI watchdog to use reference cycles
on Intel systems.  This is actually more accurate than cycles,
because cycles can tick faster than the measured CPU Frequency
due to Turbo mode.

The ref cycles always tick at their frequency, or slower when
the system is idling. That means the NMI watchdog can never
expire too early, unlike with cycles.

The reference cycles tick roughly at the frequency of the TSC,
so the same period computation can be used.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: http://lkml.kernel.org/r/1465478079-19993-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 11:16:59 +02:00
..
acpi Merge branches 'acpica-fixes', 'acpi-video' and 'acpi-processor' 2016-06-03 22:35:05 +02:00
asm-generic locking/qspinlock: Fix spin_unlock_wait() some more 2016-06-08 14:29:08 +02:00
clocksource
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-05-19 09:21:36 -07:00
drm Merge tag 'drm-intel-next-fixes-2016-05-25' of git://anongit.freedesktop.org/drm-intel into drm-next 2016-05-27 16:08:38 +10:00
dt-bindings Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2016-05-26 09:23:43 -07:00
keys
kvm KVM: arm/arm64: vgic-new: implement mapped IRQ handling 2016-05-20 15:40:09 +02:00
linux perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86 2016-06-14 11:16:59 +02:00
math-emu
media [media] media: rc: reduce size of struct ir_raw_event 2016-05-07 10:34:17 -03:00
memory
misc cxl: Add kernel API to allow a context to operate with relocate disabled 2016-05-11 21:54:10 +10:00
net packet: compat support for sock_fprog 2016-06-09 23:41:03 -07:00
pcmcia
ras
rdma IB/core: Make all casts in ib_device_cap_flags enum consistent 2016-06-07 09:50:55 -04:00
rxrpc
scsi Merge branch '4.7/scsi-queue' of git://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi into for-4.7-zac 2016-05-09 12:34:39 -04:00
soc ARC updates for 4.7-rc1 2016-05-19 09:46:18 -07:00
sound ASoC: Updates for v4.7 2016-05-16 14:59:00 +02:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2016-05-28 12:04:17 -07:00
trace - move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat 2016-05-27 13:41:54 -07:00
uapi Merge branch 'linus' into perf/core, to pick up fixes before merging new changes 2016-06-14 11:14:34 +02:00
video imx-drm probing fix 2016-05-25 12:36:20 +10:00
xen
Kbuild